Generic methods are used to produce multilayer semiconductor, glass or ceramic composites. One important application relates to the production of multilayer photovoltaic cells.
One of the main limitations in the production of multilayer cells is the incompatibility of the lattice structures of the individual semiconductor materials with respect to their dimension (size) and shape. In the production of the individual layers by direct growth of layers on one another, this limitation leads to defects in the semiconductor layer, which has been implemented with it. These defects adversely affect the quality of the produced layer and especially the attainable efficiency for the conversion of light into electrical energy. Limitations with respect to the following parameters result from this in practice:
a) the number of attainable active layers in the structure. This is limited at present to a maximum of two to three layers due to the above-described problems.
b) optimization of the individual layers with respect to the optimum wavelength range. In practice, it is not currently possible to optimize the individual layers with respect to the optimum wavelength range and associated conversion characteristics for the conversion of light into electrical energy, since compromises must always be reached with respect to the compatibility of the lattice structure.
c) use of more favorable materials. For certain wavelengths it would be desirable to use, for example, silicon or germanium since these materials would allow an ideal compromise between efficiency and costs. However, the use of these materials is often not possible since the lattice structure is not adequately compatible with the other structures which are used in the cell.
And advantage of this invention is a method which enables the production of the aforementioned multilayer composites more efficiently and with more diverse parameters.
This advantage is achieved with the features of claims 1, 2 and 4. Advantageous developments of the invention are given in the dependent claims. All combinations of at least two of the features given in the specification, the claims and/or the figures also fall within the framework of the invention. At the given value ranges, values within the indicated limits will also be considered to be disclosed as boundary values and will be claimed in any combination.